Relapse to drug and food seeking presents a significant public health concern as excessive preoccupation with drug or food seeking and taking contributes to numerous negative health outcomes. Using a rat model of reward seeking, this application aims to identify gene expression patterns in the brains of rats with a history of sucrose self-administration under short or long-term abstinence conditions known to produce low or high levels, respectively, of reward seeking (incubation of craving). In addition, some rats will experience abstinence in an enriched environment, a manipulation we have previously demonstrated to attenuate incubation of sucrose seeking. Gene expression will be visualized in the first Aim using Fos immunohistochemistry to map sucrose-cue activated regions. Aim 2 will utilize this mapping information to focus on discrete brain regions to isolate and quantitate dopamine D1 receptor signal cascade proteins, some in basal vs. phosphorylated states, as we have found that D1 receptor antagonism has time-dependent (incubation-dependent) effects on sucrose seeking. Beyond the goal of identifying neural substrates of addiction as a means to informing novel addiction therapies, the studies will be conducted as a means to expose undergraduate researchers to the scientific process. Engaging the students in this way will enhance their training experiences and the research environment at Western Washington University.